1. Technical Field
The present invention relates to photovoltaic devices and methods for fabrication, and more particularly to devices, structures and fabrication methods that improve efficiency by adjustment of deposition power of a buffer layer and/or a p+ layer.
2. Description of the Related Art
A barrier height is a difference between work functions of different materials. The barrier height is affected by the type of material with which the semiconductor is in contact. A band offset is the measure of misalignment between energy levels at the interface between two solids. The offset between an electrode and a semiconductor is called a “Schottky barrier”. The barrier height and offset are measures of how much a given material resists the flow of electrical charge through a medium. Both semiconductor-semiconductor band offset and semiconductor-electrode Schottky barrier decrease solar cell efficiency.